一种磁性介孔硅纳米探针及其对Fe~(3+)的识别和脱除

制备了一种可用于Fe~(3+)检测和脱除的香豆素类磁性介孔硅纳米探针MMS-C,通过TEM、FT-IR、XRD、N2吸附手段表征了其结构。性能测试结果表明,MMS-C在甲醇中对Fe~(3+)表现荧光猝灭的响应和较高的识别选择性。此外,MMS-C对Fe~(3+)具有一定的脱除能力,脱除率为38.9%。     

磁驱动超疏水海绵制备及油水分离性能

采用浸渍法,以纳米Fe_3O_4和硬脂酸对聚氨酯海绵进行了表面改性,制备了磁驱动超疏水海绵,并对其进行了XRD、FTIR、TG、接触角测试。结果显示:改性后的海绵水接触角高达158?,热稳定性较原始海绵明显提高,弹性性能未遭到破坏,置于高温(热水50～90℃,热空气80～120℃)、强腐蚀溶液(pH=2～13)的苛刻条件下24 h后,水接触角仍然高于148?。将改性后的海绵用于油/水混合物的分离中,表现出了优异的分离能力,且可通过磁铁进行磁驱动和磁回收。     

液固磁稳定床研究进展

鉴于液固磁稳定床在石油化工、生化工程及环境工程等领域具有广阔的应用前景,本文从流体力学特性、传质过程、返混与扩散等几个方面,对液固磁稳定床的研究进展进行了综述。     

Well‐Combined Magnetically Separable Hybrid Cobalt Ferrite/Nitrogen‐Doped Graphene as Efficient Catalyst with Superior Performance for Oxygen Reduction Reaction

Catalysts with low‐cost, high activity and stability toward oxygen reduction reaction (ORR) are extremely desirable, but its development still remains a great challenge. Here, a novel magnetically separable hybrid of multimetal oxide, cobalt ferrite (CoFe₂O₄), anchored on nitrogen‐doped reduced graphene oxide (CoFe₂O₄/NG) is prepared via a facile solvothermal method followed by calcination at 500 °C. The structure of CoFe₂O₄/NG and the interaction of both components are analyzed by several techniques. The possible formation of Co/Fe N interaction in the CoFe₂O₄/NG catalyst is found. As a result, the well‐combination of CoFe₂O₄ nanoparticles with NG and its improved crystallinity lead to a synergistic and efficient catalyst with high performance to ORR through a four‐electron‐transfer process in alkaline medium. The CoFe₂O₄/NG exhibits particularly comparable catalytic activity as commercial Pt/C catalyst, and superior stability against methanol oxidation and CO poisoning. Meanwhile, it has been proved that both nitrogen doping and the spinel structure of CoFe₂O₄ can have a significant contribution to the catalytic activity by contrast experiments. Multimetal oxide hybrid demonstrates better catalysis to ORR than a single metal oxide hybrid. All results make the low‐cost and magnetically separable CoFe₂O₄/NG a promising alternative for costly platinum‐based ORR catalyst in fuel cells and metal‐air batteries.     

光激化学发光免疫检测探针材料的设计与制备

光激化学发光免疫检测具有无背景荧光干扰、均相免洗的优势,在体外诊断快速检测领域中具有重要的应用前景。然而,该检测技术所用探针材料的稳定可控制备仍是该技术产业化应用的主要难点之一。采用PVP调控的共聚法,制备的负载铕螯合物Eu(DBM)₃Phen和硫氧杂环己烯衍生物PCU的聚苯乙烯纳米球作为受体球。采用介孔二氧化硅包覆,制备的负载光敏剂Ce6的Fe₃O₄@mSiO₂纳米球作为磁控驱动的供体球。利用扫描电子显微镜、透射电子显微镜、能谱仪等手段对受体球和磁控供体球进行表征。结果表明：受体球呈规则球形且尺寸均一,平均粒径约为200 nm,易分散于水,能与单线态氧作用而发光,最大发射波长约为615 nm;磁控供体球呈球形核壳结构,平均粒径约为700 nm,易分散于水中,在波长680 nm光照下能产生单线态氧,可用磁铁分离。分别用兔IgG和羊抗兔IgG修饰磁控供体球和受体球,结果显示两者之间能发生有效的特异性结合,用磁铁分离去除非特异性结合的探针球后,成功测得光激化学发光信号,证明了两种探针材料的成功制备。     

干法选煤评述

文章以大量详实的资料,回顾了干法选煤技术的理论与实践研究成果和取得的新进展,指出了研究先进高效的干法选煤技术对顺应我国煤炭工业战略西移,促进洁净煤事业的全面发展的重要意义。     

磁助捕集分离制样/X射线荧光测量微量Tc

建立了磁助捕集分离制样(MASP)/X射线荧光分析微量Tc的方法,使用磁化树脂作为固相捕集剂捕集溶液中的锝,利用外加磁场快速分离制样,实现捕集、分离及制样同时完成,可直接使用X射线荧光测量样品Tc含量。研究并分析了反应时间、磁化树脂用量、液相体积及酸度等因素对测量的影响,给出了推荐测量分析流程。使用磁助捕集分离制样,对Tc的检出限为0.33mg/L,满足PUREX流程1AW工艺点测量Tc的要求。     

Simulation of the effect of a magnetically insulated anode on a low-power cylindrical Hall thruster

The intersection point of the characteristic magnetic field line (CMFL) crossing the anode boundary with the discharge channel wall,and its influence on thruster performance and the energy and flux of ions bombarding the channel wall,have been studied numerically.The simulation results demonstrate that with the increase in distance from the crossover point of the CMFL with the channel wall to the bottom of the thruster channel,the ionization rate in the discharge channel gradually increases;meanwhile,the ion energy and ion current density bombarding the channel wall decreases.When the point of the CMFL with the channel wall is at the channel outlet,the thrust,specific impulse,and efficiency are at a maximum,while the ion energy and ion current density bombarding the channel wall are at a minimum.Therefore,to improve the performance and lifetime of the thruster,it is important to control the point of intersection of the CMFL with the channel wall.     

超导磁体技术与磁约束核聚变

目的  磁约束核聚变是解决能源问题的有效途径之一。为了实现准稳态运行,超导磁体（特别是高场高温超导磁体）已成为未来托卡马克设计的首选方案。 方法  介绍了EAST的最新实验进展及未来研究计划,并从超导磁体技术方面总结了未来聚变装置CFETR的最新进展。 结果  2021年底,世界首个全超导托卡马克EAST（Experimental Advanced Superconducting Tokamak）成功实现1056 s长脉冲高参数等离子体运行,创造最长运行时间的世界记录。 结论  中国聚变工程试验堆（CFETR, China Fusion Engineering Test Reactor）的设计已经完成,它将填补国际热核聚变实验堆（ITER, International Thermonuclear Experimental Reactor）和示范堆（DEMO）间的空白。     

Emerging techniques for assisting and accelerating food freezing processes: A review of recent research progresses

Freezing plays an important role in food preservation and the emergence of rapid freezing technologies can be highly beneficial to the food industry. This paper reviews some novel food freezing technologies, including high-pressure freezing (HPF), ultrasound-assisted freezing (UAF), electrically disturbed freezing (EF) and magnetically disturbed freezing (MF), microwave-assisted freezing (MWF), and osmo-dehydro-freezing (ODF). HPF and UAF can initiate ice nucleation rapidly, leading to uniform distribution of ice crystals and the control of their size and shape. Specifically, the former is focused on increasing the degree of supercooling, whereas the latter aims to decrease it. Direct current electric freezing (DC-EF) and alternating current electric freezing (AC-EF) exhibit different effects on ice nucleation. DC-EF can promote ice nucleation and AC-EF has the opposite effect. Furthermore, ODF has been successfully used for freezing various vegetables and fruit. MWF cannot control the nucleation temperature, but can decrease supercooling degree, thus decreasing the size of ice crystals. The heat and mass transfer processes during ODF have been investigated experimentally and modeled mathematically. More studies should be carried out to understand the effects of these technologies on food freezing process.